ISLAMABAD/KABUL – The United States has unleashed an unprecedented number of missile attacks by unmanned drones in northwest Pakistan over the last two weeks, including on Thursday that officials said killed 12 alleged insurgents at a meeting of Taliban commanders. The barrage signals the US President Barack Obama administration's intent to press ahead with a tactic that has killed scores of insurgents over the last two years but is also raising fresh anger in a nation allied with Washington. On the ground, it means fear-filled, sleepless nights. "We have become used to the drone attacks, but now people are scared as they are coming every night," said Israr Khan Dawar, a 17-year-old student in Mir Ali, a town in the insurgents-riddled North Waziristan region. "More noise means they are flying lower, and that means an attack is more likely," he added. A UN investigator said the surge added to the need for the cloak of secrecy to be lifted from the CIA-run programme, which has killed civilians as well as insurgents. Critics said the programme did more harm than good because it fans anti-US sentiment and anger at Pakistan's own government. On Thursday morning attack involved two missiles hitting a compound where a group of militant leaders were meeting, and authorities were probing whether Pakistani Taliban chief Hakimullah Mehsud was there at the time. The attack hit the Pasalkot area of North Waziristan. Two of the 12 dead were foreigners, said two intelligence officials, who spoke on condition of anonymity because they were not authorised to speak to the media. Meanwhile, intelligence officials and insurgents has said Pakistani Taliban chief Hakimullah Mehsud is alive and was not killed by a US missile strike. The missiles slammed into a former school where Pakistani Taliban leaders were meeting yesterday. Twelve people were killed in the North Waziristan tribal region neighbouring Afghanistan. Reports quickly circulated that Mehsud died. Meanwhile, in Kabul NATO said the death toll from a suicide bombing in a busy market district in central Afghanistan had risen to 20. A district police chief said the attacker apparently was targeting a regular meeting of NATO and local officials and tribal elders that was happening near the blast. Omar Khan said he was at the meeting when the blast occurred but the building was heavily guarded and it would have been hard for the bomber to enter. NATO spokesman Lt. Nico Melendez in Kabul said he had no indication of a NATO connection to the blast. Thursday's attack occurred in the town of Dihrawud, in Uruzgan province, as the area was packed with shoppers and vendors gathered for the weekly bazaar. Police said three children were among the dead. Provincial governor Asadullah Hamdan said 16 people were killed and 13 wounded in the blast. Police chief Gen. Juma Gul Himat said those killed included three children. Several shops were destroyed. Uruzgan is a mostly Pashtun province that saw major fighting in 2007. It also was the scene of a June 2002 incident in which US aircraft mistakenly attacked a wedding party, killing more than 30 people. The attack came a day after the UN released a report showing that the number of Afghan civilians killed in war-related violence was at its highest level last year, and suicide bombings and other attacks blamed on insurgents were the leading cause of death.